Precise information on the impact location of spacecraft launch hardware is required to calibrate preflight hazard predictions. Launch hardware include nonessential orbital spacecraft hardware such as nose fairings and fuel stages that are separated from the spacecraft and do not reach orbit, but return to earth along a hardware trajectory. Launch hardware impact data is required to recover expended launch hardware or test equipment. Ground-based sensors are limited in ability to obtain the impact location for hardware that impact outside of monitoring ranges. At present, launch vehicles collect data and maintain communications with ground stations for the portion of the flight where the launch vehicles are in view of the stations. Launch hardware is tracked during ascent by ground-based tracking systems. Communications and tracking on suborbital stages and payload fairings ends when the expended fuel stage or fairing has completed the launch mission when the launch hardware is released from the launching vehicle, and passes out of the view of ground-based tracking systems. Impact locations for expended launch hardware continue to be of interest for safety reasons and for potential reuse of the expended hardware.
Prior to launch, estimates are made as to where the expended hardware will land. Safety regulations specify that this hardware must land in a safe area, away from land masses or critical structures such as oil drilling platforms. The launch trajectory is adjusted to assure that safety requirements are met. Because the expended launch hardware is not tracked to impact, no data is available to verify that the hardware actually impacts in the predicted impact area. A system for returning information on the precise location of impact of a statistically significant number of expended stages and hardware is desired.
In addition, a cost-effective technique for acquiring aerodynamic heating rates on a large number of ascending launch vehicles are required to verify and possibly modify the thresholds for release of the launch hardware such as the fairings that protect payloads from atmospheric influences during launch. Imprecise estimations and the lack of precise launch data results in higher altitude of launch hardware and fairing releases, thereby increasing the mass of payloads carried to orbit by as much as 5 to 10%.
Tracking systems have been developed for commercial trucks, trains, and other modes of transportation. These systems collect GPS data on the vehicular location and return tracking information via satellite to a collection point. These systems typically draw power and data from the host vehicle. The weight and expense of existing tracking systems and services from a host increases the cost for launch systems rendering tracking systems expensive and impractical for inclusion on many launch vehicles. Electrical systems are not normally disposed on separated fuel stages, which disadvantageously create potentials for accidental fuel leakage and explosions, and hence, are not placed on fuel stages. These and other disadvantages are solved or reduced using the invention.